>>>>Is this really true? I was under the impression that the porosity
>>was governed by the % acrylamide and by the ratio of acrylamide/bis
>>(or other cross-linker). The concentration of TEMED and/or
>persulphate
>>shouldn't have any effect unless they become limiting - so that the
>>gel fails to polymerise completely no matter how long it is left.
>>Since they only catalyse the polymerisation of the acrylamide monomer
>>they play no real role in the eventual structure of the gel.
>> Can someone correct or confirm my assumption?
>> Bernard
You're assuming that the cross-linker reacts with the same kinetic parameters
as the monomer. T'aint so. Thus, changing APS or TEMED concentrations will
change the relative reactivities of the cross-linker and the monomer, and
consequently, pore size.
Now, whether the change significantly alters your gel ... that's another
question. That's why I suggested, in my original response, that you try it
with several samples which would also be run under the original conditions.
Chances are that a modest change will have little visible effect (famous last
words).
JCF